Artificial material having modified characteristics and method of making same



Patented Feb. 22, 19

DICE? ARTIFICIAL MATERIAL G MODIFIED CHARACTERISTICS o WTHOD @F MAKINGSAME' William Whitehead, Cumberland, assignor to Celanese Corporation ofAmerica, a com.

tion or Delaware No Drawing.

Application April 3, 1935,

Serial No. 14,473

' 4 Claims.

This invention relates to the preparation and manufacture of yarns,filaments, fabrics and other articles from artificial materials which,after formation, are chemically treated to modify their 5 physicalcharacteristics, and more particularly to the method of chemicallytreating the yarn whereby the amount of physical change is made visibleto theeye by means of an indicator or similar material. This inventionparticularly relates to the preparation and manufacture -of yarns,filaments, fabrics and other articles containing organic esters ofcellulose wherein at least a part of the filaments employed are treatedwith.a basic material to alter the acid value of the material or tosensitize the same for saponification.

An object of the invention is the economic and expeditious production oftextile materials containing yarns and filaments of an organic materialespecially an organic ester of cellulose, which materials are so treatedthat any degree of physi-" cal or chemical modification, such assaponification or sensitization for saponiflcation, is registeredthrough an indicator such that the operator may readily, and without theaid of instruments,

ascertain the degree of treatment that the mate rials have undergone, orto ascertain which part of the materials have been treated. A furtherob-- ject of my invention is the production of textile 0 materials andfabrics, which contain yarns of organic esters of cellulose, which havebeen periodically treated with a saponifying or sensitizing agent andalso with an indicator such that,

I upon visual inspection of the yarn and fabrics, 35 the locality of thesaponification and/or sensitizing may be easily ascertained. A stillfurther ob- Ject of the invention is theproduction of yarns andfilaments which are so lubricated and/or treated that they are madeparticularly ame- 4o nable to textile operations and subsequent chemicaltreatments. Other objects of the invention will appear from thefollowing detaileddescription.

cals or in any other manner to change their char- I 50 acteristics,which change although difilcult to see with the naked eye, neverthelesschanges the pH value at least at the surface of the yarn, thus making achange in the color of the indicator which becomes readily visible.Thus, by employ- I ing this invention, very minute changes or Byemploying this invention, which in general 5 consists in applying toyarns and filaments a lunar-2o) changes not readily seen with the eyemaybe made in the fabric, yarns and filaments, yet due to the highlysensitive indicator a fairly close observation may be kept on the extentand locality of the treatment. In this manner a much more uniformmaterial may be produced, as the operator can watch immediately uponapplication of the treatment the extent of that treatment and, make anyadjustments necessary to make the treatment uniform. Although thisinvention has 10 many uses, it is of particular applicability in thevarious processes wherein organic esters of cellwlose are saponified.Thus, in the treatment of yarns and filaments or fabrics containingorganic esters of cellulose with a saponifying agent which 15 merelyetches or partially saponifies the same, or sensitizes the same so thatthe sensitized materials may be developed in soap bathspetc. in latertreatments, this invention is of great advantage in that the partialsaponification of the yarn, 20 which is sometimes so slight as not to beidentified without the use of the elaborate means for weight ing theyarn, etc., is made obvious to the eye due to the change in the color ofthe indicator at the places which have been contacted by the saponifyingagent; This invention also may be used with advantage in the treatmentof yarns wherein the yarns are saponified throughout their length,

in whichcase any differencev in the amount of application ofsaponifyin'g agent on various increments of the yarn that may produce astreaky appearance on the yarn may be indicated by the change in thecolor of the indicator and thus allow for change intreatment to correctany'lack of uniformity.

:A further advantage of this'invention is that the yarns" and filamentsmay be coated with a lubricant which allows for the material to passthrough guides, needles, etc. and to be formed into fabrics of finestitch shape. .The lubricant, which 40 preferably contains the colorindicator, may be selected according to the subsequent treatment to begiven the yarn; Thus, when the yarn'is to-be subsequently saponified,non-saponifiable oils containing an acid color indicator may be employedas the lubricant, which lubricant, although conditioning the yarn forall textile operations, does not interfere with the saponification, orsensitizing by partial saponificatlon, in the subsequent treatments.

In accordance with my invention, I incorporate with yarns or filamentsor other artificial materials a lubricant containing a color indicator,which incorporation is preferably made by coating' the yarn: with anoily material containing an 55 apply a coating of a non-saponifiablelubricant containing an acid dyestuif to yarns and filaments during awinding operation and then apply to the yarns or filaments or fabricsmade therefrom, either in localized areas or the entire surface thereof,either a basic material capable of at least partially saponifying thematerial to an extent sufficient to sensitize those parts coated withthe basic material, or a saponifying agent of sufficient strength or fora sufficient length of time and temperature to materially saponify thematerial.

This invention is applicable to the treatment of yarns, filaments orother artificial materials formed of any suitable ester of cellulose orother artificial material. For instance, I may employ this invention inthe treatment of yarns and filaments formed from the nitrates ofcellulose, the organic esters of cellulose, cellulose others, orregenerated or reconstituted cellulose made by either the cuprammoniumor the viscose methods. Examples of organic esters of cellulose andcellulose ethers that may be employed are cellulose acetate, celluloseformate and cellulose propionate as the cellulose esters, while examplesof cellulose ethers are methyl cellulose, ethyl cellulose and benzylcellulose. The yarns or filaments containing these organic esters ofcellulose materials may be formed by either the wet or dry methods ofspinning and may contain besides the derivatives of cellulose basematerial, effect materials such as pigments, dyes, lakes, fillers,plasticizers and lubricants,

Any suitable artificial material, or for that matter natural textilematerials such as cotton, wool and the like, may be coated with acoating containing a lubricant and a color indicator, which colorindicator and lubricant are chosen according to the subsequent treatmentto be given the material. However, for application to textile materialsformed of or containing organic esters of cellulose, which are to besubsequently treated with a base material for any purpose such assensitizing the same for saponification in soap solution or forthe'partial, intermittent, or total saponification, the textilematerials may be lubricated with. a lubricant which is non-saponifiableand does not form a soap with the basic material used in the saponifyingoperations. Accordingly, theremay be used any of the following: mineraloils, fatty alcohols, glycerols, glycols, their substitution productsand derivatives, or combinations of these materials. An example of asuitable combination of these materials is a fatty alcohol dissolved inmineral oil. It is preferable, when treating an organic ester ofcellulose with a basic material, however, to incorporate with thetextile materials a sulphonated naphthene dispersed in mineral oils as abetter spread on the artificial material is obtained in this way and,also, the sulphonated naphthene acts to make the lubricant easilyemulsifiable and readily scoured free from thematerial. Althoughvegetable oils are usually saponifiable, certain quantities of the samemay be mixed with the unsaponifiable lubricants named above.

- As a preferred lubricant. for the treatment of organic esters ofcellulose which are to be subsequently treated with a basic material, Imay use one containing an acid color dissolved in sulphonated naphthenewhich in turn is dispersed in amineral oil. This dispersion may beapplied to the yarns or filaments by applying the same with a furnishingdevice during any winding operation. Any suitable furnishing device maybe employed, such as a wick or a roller dipping into the lubricatingmaterial and contacting with the travelling yarns and filaments as theyare being wound upon a package. Although it is preferable to apply thelubricant during the winding operation, the same may be applied in anyother suitable manner such as by hank dipping, forcing the lubricantthrough packages of the material, or by adding the lubricant to thespinning solution from which the yarns and filaments are formed.

Any suitable acid color dyestuif may be employed as the, color indicatorto be dissolved or dispersed in the lubricant when treating organicderivatives of cellulose. These acid colors are usually very goodindicators to make visible the pH concentration of the medium containingthem. For example, there may be employed such acid colors as Violet BK,Methyl Green, Acid Green and similar acid colors that belong to thegroup of diand tri-amino derivatives of triphenylmethane anddiphenylnaphthylmethane coloring matters. Other coloring matters thatchange color upon a change of pH value or upon the presence of specificreagents may be employed. When employing organic derivative of celluloseyarn, the above acid colors are of particular advantage because they maybe easily scoured from the yarn. In treating yarns of other materials,indicators that merely tint the yarn and do not dye the same maylikewise be selected.

After the yarns or filaments have been lubricated in accordance withthis invention, they may be formed into fabrics in any suitable manner.The lubrication may be effected prior to any subsequent chemicaltreatment, and before forming the yarns into a fabric. The chemicaltreatment may be carried out during the same winding operation in whichthe lubricating step is effected or during a subsequent windingoperation. When it is desired to chemically treat, such as by asaponifying agent, fabrics formed from yarns or filaments containing anorganic ester of cellulose, as by printing a design upon the fabric witha saponifying agent or treating the whole of the fabric with asaponifying agent, the lubricated yarns or filaments may be employed inthe fabric in any suitable manner to efficiently distribute the colorindicator throughout the fabric or that part of the fabric to betreated. Lubricated yarns having the indicator thereon may be employedas the warp threads of the fabric or the weft threads of a fabric or asboth warp and weft threads. These yarns may contain filaments made ofother materials, such as yarns or threads of organic derivatives ofcellulose that do not contain an indicator, wool, cotton, silk, flax,etc., or the lubricated yarns containing the color indicator may bewoven into fabrics along with such other yarns or threads in anysuitable manner. The fabrics may be formed of these threads, orcombination of threads, by weaving, warp knitting, circularknitting,netting and knotting.

This invention is particularly applicable to the treatment of yarns oforganic esters of cellulose as the same are formed, that is, a lubricantcontaining color indicator is applied prior to the first windingoperation, thus giving to the yarns a color which makes themidentifiable throughout the subsequent processes, which yarns are laterto be sensitized for saponification during a subsequent Windingoperation. The yarn containing the lubricant and color indicator may becaused to contact, or periodically contact, with a furnishing devicesupplying a saponiiying agent to the yarn in sumcient amount to merelyetch the surface of the yarn by the saponifying action, which treatmentmay be termed sensitizing the yarn, as the yarn if later treated with asoap solution, saponifles in those rts which are etched, while theunetched portions are unaffected by the soap solution. This partial'saponification or sensitizing, as it is applied during a windingoperation, is' commercially limited by the amount of caustic that may besafely applied in such a way that the saponifying action actually takingplace at this point is very light. For instance, the saponification iscarried to such an extent that the loss in weight of the yarn at thoseparts sensitized is from 2 to 7%. This very light sapcnification,although capable of being developed in later treatments to a very heavysaponification, is nevertheless so light that it is dicult to observe atthis stage. With the color indicator upon the yarn, however, those partsof the yarn contacted by the saponifying agent changes the pH value atthe surface of the yarn, thus giving an obvious change in color to theindicator. The operator, under these conditions, may readily see howmuch of the area is being contacted by the saponifying agent merely bycomparison of colors. The sensitizing or saponifying agent employed totreat the yarns, filaments or fabrics containing an organic ester ofcellulose may be any suitable saponifying agent having a, pH valueoffrom 10.5 to 14. Any suitable basic solution may be employed for thispurpose, such as an aqueous solution or an alcoholicsolution of analkali hydroxide, for instance, sodium hydroxide or potassium hydroxide,an aqueous solution of ammonium hydroxide, a salt of a strong base, suchas ammonia or alkali, and a weal: acid such as organic acids, organiccompounds having a basic reaction, etc. Examples of salts of a strongbase and an organic acid which may be employed for this inventionaresodium acetate, potassium acetate, etc. Examples of organic bases thatmay be employed as the sensitizing or saponifying agent are the primary,secondary and tertiary amines, for instance, ethanolamine, methanolamine, di-methanol amine, di-ethan'ol amine, tri-methanol amine andtri-ethanol amine. Also, quaternary ammonium bases may be employed, forinstance, tetramethyl ammonium hydroxide, tetraethyl ammonium hydroxide,etc. These materials may be applied to the yarn from aqueous solutions,which solutlons may be of any suitable concentration such that the. pHvalue of the solution is above 10. These and similar saponifylng orsensitizing agents do not materially interfere with the lubricatingcoating originally applied to the yarn, especially when said coatingcomprises an acid color in sulphonated naphthene dispersed in mineraloil or an acid color dissolved in a. mixture of a glycerol or a glycol,their derivatives or substitution products, and any suitablenon-saponifiable oily material. When treating fabrics with a saponifyingagent, the same may be applied by special devices such as a printingmachine, etc.

Thus, in carryingout my inventiom -a yam treated at formation with alubricant containing a color indicator such as Violet 5 BK is of a deepblue color. When this yarn is contacted by a saponiiying agent, thatpart of the yarn contacted changes to a red or a color between blue andred, depending upon the concentration of the hydrogen ion in thesaponifying material, which concentration governs the shade or color ofthe indicator. In the partial saponification of organic esters ofcellulose, the locality of treatment, may be readily ascertained. Inother tym of treatment even the extent of treatment as well. as thelocality may be indicated, especially in treatments that do not formsalts.

As an aid to illustrating this invention and not as a. limitation, thefollowing example is given:

Example An acetone soluble cellulose acetate yarn is formed by the drymethod of spinning and prior to being wound into a. package it is causedto contact with a wich supplying thereto a coating comprising i i of anacid color, Violet 5 BK, dissolved in 20 parts of sulphonated naphthene,which in turn is dispersed in 75 parts of light mineral oil, in such amanner that the lubricant adhering to the yarn amounts to about 5% basedon the weight of the yarn. The yarn thus produced is of a bright bluecolor and sufflciently lubricated for all textile operations.

This yarn is then re-wound and during the rematerial is found not tointerfere with the speed or depth at which the saponifying agentattaclrs the yarn, nor is the lubricant decreased in value or altered inany manner to cause the yarn to become less adaptable for textileoperations such as weaving, etc.

Although this invention has been described somewhat in detail withreference to applying the treatment during a winding operation, itnevertheless has applicability to the treatment of fabrics formed oflubricated yarns, the lubricant of which contains a. color indicator.The fabric thus produced will be of a solid blue color and printingpaste may be applied thereto containing saponifying agents in anysuitable concentration to give a light or heavy saponiflcation, and theparts contacted or printed with such paste become readily visible due tothe change in color at the point or parts contacted with the saponifyingents. This invention has also been described somew in detail withreference to the lubricating of yarns for the purpose of indicating theextentpi area of saponification. It is nevertheless applicable totreatment of yarns with materials other than saponifying agents. Forinstance, color indicators may be employed when treating the yarns withany reagent which alters the pH value of the surface of the yarn, forinstance, treatments with dilute acids, salts and similar materials forthe purpose of producing shrinkage,

crepe or other desired effects in the material, or

visible the extent and concentration of treatment.

In the selection of the lubricant and color indicator, it is usuallypreferable to select -such a lubricant that may be readily scoured freefrom the material and such a color indicator that has no afilnity forthe material being treated and thus does not permanently stain thematerial and interfere with dyeing operations or the production ofmaterial of natural color. Any suitable amount of lubricating materialmay be applied to the yarn, for instance, from 1 to 20% or more oflubricant on the weight of the yarn. The lubrieating material maycontain from 1 to 10% of a coloring or tinting compound as an indicator.

It is to be understood that the foregoing detailed description is givenmerely by way of illustration and that'many variations may be madetherein without departing from the spirit of my invention.

Having described my invention, what I desire to secure by Letters Patentis:

i. In a process for saponifying yarns, filaments, fabrics and likematerials having a basis of a cellulose ester by treatment with analkaline reagent, the step which comprises indicating changes in the pHvalue on the materials during the saponification by means of a coatingapplied to the materials, said coating containing a fugitive coloring pHindicator, whereby the extent or degree of saponification may be visiblyascertained.

2. In a process for saponifying yarns, fllaments, fabrics and likematerials having a basis of cellulose acetate by treatment with analkaline reagent, the step which comprises indicating changes in the pHvalue on the materials during the saponiflcation by means of a coatingapplied to the materials, said coating containing a fugitive coloring pHindicator dispersed in a scour.- able lubricant, whereby the extent ordegree of saponlflcation may be visibly ascertained.

3. In a process for locally saponifylng yarns, filaments, fabrics andlike materials having a basis of cellulose acetate by treatment with analkaline reagent, the step which comprises indicating local changes inthe pH value by means of a coatingapplied over the whole surface of thematerial prior to the saponification treatment, said coating containinga fugitive coloring pH indicator dispersed in a scourable lubricant,whereby the extent or degree of saponification may be visiblyascertained.

l. In a process for saponifylng yarns, filaments, fabrics and likematerials having a basis of cellulose acetate by treatment with analkaline reagent, the step which comprises indicating changes in thepl-l value on the materials during the saponiflcation by means of acoating applied to the materials, said coating containing an acid colorhaving no dyeing aflinlty for the cellulose acetate, whereby the extentor degree of saponification may be visibly ascertained.

WEMAM WEHTEHEAD.

